The invention relates to a drive system for regulating devices in motor vehicles. From an International Patent Application No. WO 01/89063 A1 a drive unit is known for regulating devices in motor vehicles having the features of the preamble of claim 1. Since with this known drive unit at least one component part of the disc armature motor such as for example the drive shaft, the magnetic short circuit or the housing shell on the motor side also undertakes an additional mechanical function of the planet wheel transmission and/or a mechanical component part such as the housing shell on the gearing side undertakes a function of the disc armature motor the drive unit is as a result of the multiple use of individual component parts characterised by a minimum number of parts and minimum weight as well as following the interfitting box structure and thus the high degree of integration of the component parts of the drive unit by a small volume and more particularly by its flat method of construction.
As opposed to the drive units normally used comprising rod armature motors with worm gearing as reduction gearing which through their type of construction are not equally suited to right and left hand vehicle doors where the structural height in the door region is an interference and whose installation position is not flexible particularly through rotation of the drive unit, wherein the centre of gravity of the motor lies outside of the screw connection of the drive unit and whose system mass is very high, the drive unit according to the International Patent Application No. WO 01/89063 A1 is particularly suitable for installation in vehicle doors as a result of its properties previously mentioned since it can be incorporated without problem in a base part, door module or a support plate in any angular position and independently of which door side and provides a single assembly plane and thus a variable use.
A further reduction in the structural volume of the drive unit known from the International Patent Application No. WO 01/89063A1 comes up against stability limits if the material thickness of the component parts of the drive unit used is reduced and the distances between the component parts which are already boxed in each other with a high degree of integration are reduced. Thus the small air gap between the armature disc and the permanent magnet of the stator of the disc armature motor in the case of a stable mounted armature disc which is not permanently precisely aligned would lead to contact between the armature disc and permanent magnets and thus to premature wear and breakdown of the drive unit. Furthermore the mechanical stability of the planet wheel transmission would be endangered if the centring of the mechanical component parts is not permanently guaranteed and also under severe strain no deformations of the gearing parts occur.
The object of the present invention is therefore to provide a drive system for regulating devices in motor vehicles of the type mentioned at the beginning which ensures a further reduction in the structural volume and more particularly an extremely flat method of construction without impairing the functioning, mechanical stability and durability of the drive unit.